(Much) more efficient solar cells

[Rabishu]

So, a number of years ago, I made an acquaintance who happened to be a (well paid) scientist, and she told me that she, along with some colleagues, had discovered a way to make photovoltaic cells that were over 500% more effective than anything on the market.  The trick was to put a Hologram inside the glass that focused the light to the center.

Obviously, this potent (and easily-affordable) technology has not been implemented, either due to the laziness of its creators or suppression by shady corporate (non)entities.  I will not disclose who the scientist was, I doubt she would approve of this message, but I can plant the seeds...  Where they might grow.   

[exe]

Maybe its possible theoretically but practically it wont work. You never know with these scientists, sometimes they just dont see the whole picture, but ofcourse its nice if someone can get it to work.

[2xMakina]

Isn't it interesting how every new "revolutionary" idea is being "suppressed."

I'm not buying it.  It sounds like an overly simplistic solution to a very complex problem regarding the efficiency of photovoltaic cells.

The advances I am aware of are much more in-depth than putting a picture into the surface glass.  Especially since "concentrating the light to the center" does absolutely nothing to increase the photovoltaic output...it's not HEAT, people, it is light energy breaking electrons free in relatively tiny quantities that can be picked up by a physical conductor threaded through the photovoltaic strata.  "concentrating" the light in one place on the strata simply deprives the rest of the cell's surface of that light, so there is loss in one place, gain in the other.

And because any method of bending light through glass is inefficient, there will be net loss, not net gain.

Try again, sparky.  I am not convinced.  Let's see the data.

Because especially here, if someone can get it to work, we can and will implement it.

2x

[D/\taM/\gg0t_mk1]

Since Antireflective coatings are improving every year, and slowly becoming sorta affordable. ..the photon throughput will increase as the AR coatings technology improves. AR Coatings are very expensive, but they have proven to improve solar photovoltaic output. I feel this is the best way to improve photovoltaics...

 also if anyone knows his math, there is no such thing as greater than 1.0 or 100% efficiency. ...so your friend with a 500% efficient system is good with numbers. ;-)

[shovel]

I do recall around 2001 or so reading a story about a Japanese university professor who built solar cells able to operate efficiently with the entire visible spectrum as well as some UV bleed.     I believe it was quoted about 3x the net electrical energy per square inch vs. current amorphous pv technology in sunlight.     

Without getting into any wild conspiracy/suppression speculation,   I still am curious what became of that. 

[Rabishu]

OMFG!  OK you little party-poopers, let me clarify a couple things:

A)  I did not mean 500% efficiency, I meant 500% of the efficiancy of current Solar cells.  Five times as energy productive as common Photovoltaic cells.  Capish?

B)  I did not say the idea was being suppressed, I said maybe it was being suppressed.  Or neglected.

C)  Trust me, the scientist in question is a very reliable source, very professional and not some quack.  She is a government-funded physicist, among other things.

Perhaps this was the wrong forum to introduce such a potentially useful idea.  This audience would be better suited to celebrity slander.

[xenovalent]

OMFG!  OK you little party-poopers, let me clarify a couple things:

A)  I did not mean 500% efficiency, I meant 500% of the efficiancy of current Solar cells.  Five times as energy productive as common Photovoltaic cells.  Capish?

B)  I did not say the idea was being suppressed, I said maybe it was being suppressed.  Or neglected.

C)  Trust me, the scientist in question is a very reliable source, very professional and not some quack.  She is a government-funded physicist, among other things.

Perhaps this was the wrong forum to introduce such a potentially useful idea.  This audience would be better suited to celebrity slander.

Yeah, you said 500% more effective which I took to mean "5 times the output current for the same light input" rather than 500% efficient, or even 500% more efficient (the latter of which I would have read the same as what you actually did say).

Not sure that the idea's being suppressed - it may just fall under the umbrella of "not commercially viable".  The increased effectiveness could be offset by a larger (percentage-wise) increase in price.  Or it could have just turned out that there's a 5x increase in effectiveness from man-made light sources, but under sunlight, the increase is dramatically less because the material reaches a saturation point where you can't get electrons out any faster.

Or potentially, your friend realized that she had mentioned something classified and gave you a bullshit continuation of the story to throw you off the real track.

Don't worry, if this is real, it will come out eventually.  The nice thing about the laws of nature is that they are the same everywhere and can be rediscovered as many times as necessary.

[2xMakina]

Perhaps this was the wrong forum to introduce such a potentially useful idea.  This audience would be better suited to celebrity slander.

If you can't attack the idea, attack the people?  This is known as an ad-hominem attack.

It's not helping your introduction any.

Your clarifications, while helpful, still don't shed enough light (pardon the pun) on the methodology by which photovoltaics become efficient to the point of being cost-effective in the short and medium term.

Thus, my comment of "Try again, sparky."

In other words, you're going to have to bring more to the table than hearsay.  We have some pretty smart people here, some of which are UNPAID researchers who actually have to produce something in order to get paid...so we don't have time to speculate on hearsay.

In Server We Trust.

All Others Must Bring Data.


With that being said, Datamaggot has an excellent point regarding the antireflective coatings (which, to the best of my knowledge, are NOT holograms), which increase the photon throughput efficiency of the substrate (glass, polycarbonate, acrylic, etc) by causing light that would normally have been reflected to continue to pass through.

Let's clarify that.  That's not concentrating the light, nor bending it.  It is simply creating a more hospitable environment for more to pass through.

But does this increase efficiency of the cell?  Not exactly.  It increases the amount of light getting to a cell of a given efficiency.

So will the antireflective coatings cause a better energy output for the cells?  Theoretically yes.

The trouble with testing/proving the theory is whether or not the output difference is measurable.

I don't forsee an output improvement on the order of 3-5 times, however.

As I've said before, I think we will see the greatest improvement in solar efficiency with the improvement of the actual strata material, followed by improvements in the barriers between the strata material and the light source (the coatings.)

Another method that has been attempted, especially with the "foldable" amorphous solar cells, is making them more weather resistant so they need not be behind a substrate.

Jury's still out on that one.

In the meantime, there's everything currently on the market from Topray to Sunlinq.

Feel free to conduct your own experiments.

I know I need a new Sunlinq to replace the Topray solar briefcase I gave away a while back.

Maybe I'll conduct some of my own experiments and report back.

In the meantime, Rabishu...see if you can get us some specifics to work with.  I'm feeling experimental.

2x

[Rabishu]

I am no longer in touch with this acquaintance, I have changed Email addy's a few times since then.  All I can remember is that the clear part was Hologram-condusive and that the Hologram was a cheap one that simple focused the light into the center and towards the receptive materials.  G2G, maybe more L8R.

[Loopster]

So the hologram would function like a fresnel lens to focus the light to a point? I know a lot of home brew steam guys do this with regular fresnel lenses which I've wanted to build myself. I obviously dont have access to the equipment needed to make holograms but it seems possible.

The solar tech I heard was with new meta materials. Let me see what server says... yeah here it is: http://www.technologyreview.com/energy/25199/?a=f
There was also another about a black center material the reflected little or no light. These were supposed to have some pretty impressive energy boosts.

[Rabishu]

What would be cool is someone combining all these techiques.

[2xMakina]

"A solar cell coated with a material whose refractive index is identical to that of air would reflect no light at all."

Excellent find, Loopy!

Finding materials with compatible refractive indices is indeed possible.  I remember in biology we used a special oil on our slides that had the same refractive index as the glass in order to more easily see things in the microscope.

That worked.  I see no reason why finding a synthetic or meta material with the same refractive index as air, would not increase the available light to the solar cell.

Increasing the cell's efficiency AND increasing the light available to it (possibly even by bending the non-visible radiative energies such as ultraviolet and infrared into the visible spectrum where they can be utilized) could give the outputs advertised.

Been busy lately so my experimentation has come to a grinding halt.  Will return as can.

[Loopster]

I tried the pyrex with vegetable oil trick to see if it works and it does. You take a pyrex glass and put it into a bowl of vegetable oil and since they have the same refractive index it virtually disappears.

[Yugosaki]

I've been thinking about this, MAYBE the person in question means "more efficient" as in "uses less solar cell material" i.e. would be cheaper to produce a panel of the same size.

Clarification:

If you used a hologram or other means to focus the light onto one spot, you could have a glass plate collecting and refracting all the light from the whole plate onto a actual cell that is significantly smaller than the plate. This would mean that you could produce a cell of the same size and perhaps close to the same output for cheaper, since most of it would just be coated glass.

I haven't actually crunched any numbers on this, so it's just an off the cuff idea that would use the concept Rabishu is talking about.

Of course, that would mean the solar cell isn't actually more efficient, but just being used more efficiently.

[D/\taM/\gg0t_mk1]

I've been thinking about this...

Yeah, I figured the researcher was trying to build some sort of "photon funnel" using the hologram. It's just a pet peave of mine when companies (or anyone) boast incoherent math. Like 5X improvement over a technology which state of the art, already yields a 50% efficiency.

For best output from the PV Cells, the panel should be placed at a 90 degree angle from the sun. A holographic 'lens' could be used to colluminate light to a true 90 degree angle any time of day w/o moving the panel... however I think Fresnel Lenses can already be used to that end.

Then I thought, the hologram could be used on a smaller scale. A single hologram per photodiode. I guess on a small scale, holograms may be less expensive than optical lenses.